The power of an overprint to hide completely the colour underneath; also sometimes referred to as "obliterating power" or "opacity".

The spectral response characteristics of the average observer defined by the CIE. Two such sets of data are defined, the 1931 data for the 2-visual field (distance viewing) and the 1964 data for the annular 10-visual field (approximately arms length).

This term typically refers to short run colour printing. These processes include ink-jet, electrostatic and direct-to-press.

Original Equipment Manufacturer.

The preset distance between the screen and the substrate to be printed.

An unintentional or faulty transfer of wet ink from a printed sheet to another surface in contact with it. Also called setoff.

The transfer of ink from Plate to object with conventional pad printer.

A common printing process that makes prints by transferring ink from a flat plate to a rotating "blanket" that contacts the paper.

Refers to an ink system whose vehicle is oily in nature. Colloquially (but not accurately) used to describe ink thinnable with white spirit.

The measure of the amount of light that can pass through a material. Also, the property of a film that prevents "show through" of dark printing or marks on a substrate (media). "Hiding power"

Impenetrable by light; neither transparent nor translucent.

A technology that can recognise letters from a scanned image and convert them into ASCII characters to be saved as an editable text file.

The maximum physical resolution of a device. Optical resolution provides better quality than interpolated resolution of the same number, which uses software to create additional image information.

A defect which causes the ink film to dry to a glossy but uneven film like that of the skin of an orange. Considered to be due to lack of flow.

A protective clear film that extends an image's outdoor life and enhances its visual quality.

Application of a clear film to a graphic for the purpose of protection or to enhance the graphic quality.

An overprint results when one ink or varnish is printed on top of another ink or varnish.

Printing one ink or tint build over another, most commonly for trapping purposes.

A moulded silicone rubber profile used to transfer the image from the plate to the component. Also called Tampon, Dolly (as in Parton), rubber, sponge, ink transfer pad, silicone pad, bomb, t?t.

The process and software that prepares artwork, text and other elements to be collected and prepared for printing within a specific area.

Electronic formatting of multiple pages in a file for output.

Synonym for ink.

A company producing numerous colour matching systems for print and computer applications. The PMS® colour-matching system is commonly used to represent 3,000 distinct colours through a numbering system.

An electronic document format from Adobe that allows the distribution of digital files across any platform that can display a document as originally designed and formatted without having the software application or fonts on the viewing computer.

Any adhesive that is difficult to remove after application without leaving adhesive on the substrate.

An inkjet printer where the ink starts as a solid that is then heated and liquefied, and the sprayed onto the substrate.

Opaque thermoset plastics that are resistant to solvents and water.

Persistent emission of light following exposure to and removal of incident radiation. It glows when the light source is removed.

An instrument for measuring luminous intensity, luminous flux, illumination, or intensity.

Polymer that is sensitive to U.V. light. Used in temporary etched plates. Known then as Photopolymer Plates. Also one of the chemistries used in stencil emulsions. I.e. SBQ Photopolymer

Undesirable voids in the print caused when a portion of the pre-printed image sticks to the bottom of another print screen on that image.

An inkjet printing technology that uses a material that moves to pump the ink out when subject to an electric charge instead of heat to drive micro droplets through the nozzle.

The solid colouring matter in an ink.

Holes in the ink film due to localised inability to wet surface. (Reticulation and Cissing).

The smallest unit of data in a digital image. Together, the small discrete elements constitute an image that can be seen on a monitor or printed on a substrate. A pixel's code contains information relating to colour and placement within the larger image. The number of bits of tonal range capability assigned to the pixels in an image. For example RGB 24 bit colour means a pixel depth of 24 bits, 8 bits or 256 levels per colour.

Graininess in an image that results when the pixels are too big.

A measure of the density of scanned information in an image. The finer the optics of the scanner, the higher the scan resolution.

A non-fibrous, synthetic material in sheet or moulded form capable of being printed.

A non-volatile substance incorporated in an ink or plastic to improve the flexibility of the dried film.

The required image is etched onto the plate. Plates are normally either hardened steel or photopolymer. Also called Etched Plate, Plate Plate, Intaglio Plate, Printing Plate.

A term applied to a peripheral unit that, through computer control, prints data via the Cartesian (X/Y) co-ordinate system.

A unit of measurement used in the graphic arts industry. There are 12 points to a Pica. One point equals approximately 1/72 inch. See "Postscript Point."

Sign or display used in close proximity to the actual retail product being sold. Also known

The name of a defect which occurs (mainly with matt ink) when the gloss of a print is increased by rubbing.

A thermoplastic that is heat and moisture resistant. Commonly used for industrial components and also food containers and baby bottles.

A thermoplastic most commonly used in the form of DuPont's Mylar. Particularly in membrane switches and sensors.

A thermoplastic commonly used in the packaging industry. It is strong, lightweight and highly resistant to breakage. Requires pre-treatment prior to printing as the surface energy is low.

A substance, the molecules of which consist of one or more structural units repeated any number of times; vinyl resins are examples of true polymers. The name is also frequently applied to large molecules produced by any chemical process, e.g. condensation, a reaction in which the water is produced, alkyd resins are examples of these.

The process of producing a polymer.

Claimed to be the lightest commercially available thermoplastic. It has a high rigidity and surface hardness. Commonly used in the manufacture of housewares, luggage and bottle caps. Requires pre-treatment prior to printing as the surface energy is low.

A thermoplastic known for its rigidity, hardness, heat and dimensional stability as well as ease of fabrication.

The orientation of an image that is taller than it is wide; a setting controlling an output device to properly fit a computer document to the print medium. Vertical.

Characteristic of allowing a marking to be moved after initial contact by use of a combination of a two-step adhesive system. A low-tack adhesive is on the surface for moving a marking; then, under pressure, a higher-tack adhesive is released to permanently set the marking.

A special effect created by using a limited number of grey levels within an image. In computers it is created by setting a defined number of gradient steps in a bitmapped image.

A slight revision to the "Point" measurement unit. A Postscript point is exactly 1/72 of an inch. Most graphics software utilises this refined value for a point.

A page description programming language created by Adobe. That is a device-independent industry standard for outputting documents and graphics.

The length of time during storage of an ink, emulsion, etc. once mixed in a specific container under normal conditions without changing chemically to a point where its usefulness is affected.

The period after mixing the two parts of a two-pack ink, during which the ink remains usable. This also applies to single part ink and is likely to be days rather than hours.

The proof accepted by the artist that is used as the standard for comparing all subsequent prints. Some printers require a signed "proofprint" before production printing can begin.

The process colours (Cyan, Magenta, Yellow, and Black) are used in traditional colour printing to reproduce a full colour range.

A print used to evaluate the entire production process prior to printing.